The present invention relates to the manufacture of semiconductor device structures and, in particular, to a method of manufacturing such structures utilizing quantitative simulation of the effect of dopant-dopant interactions on dopant diffusion.
The difficulty of modeling defect interactions in a semiconductor material is well known. Even the deceptively simple detailing of single dopant diffusion in silicon, a material that has undergone extensive investigation because of its widespread use in the integrated circuit industry, involves invocation of a host of complex defect mechanisms. See, for example, S. M. Hu, et al., "On Models of Phosphorous Diffusion in Silicon", Journal of Applied Physics, Vol. 54, No. 12, December 1983; F. F. Morehead, "Enhanced Tail Diffusion of Phosphorous and Boron in Silicon: Self Interstitial Phenomena", Applied Physics Letter, Vol. 48, No. 2, Jan. 13, 1986; and N. E. B. Cowern, "Analytical Description for the Diffusion and Recombination of Point Defects in Silicon", Applied Physics Letter, Vol. 54, No. 15, Apr. 10, 1989.
Heretofore, attempts to detail dopant diffusion in regions where several species of impurities have overlapping populations has been avoided. Prediction of the behavior of these multiple dopant systems has been made by extrapolating from single dopant behavior to the multiple dopant domain.
Extension of current models of single dopant diffusion invoke a host of ameliorating couplings with vacancies or interstitials or both to produce varying degrees of suitable explanations of experimental results. See, for example, A. F. W. Willoughby, et al., "Diffusion of Boron in Heavily Doped N and P Type Silicon", Journal of Applied Physics, Vol. 59, No. 7, Apr. 1, 1986 and R. Deaton, et al., "Diffusion Phenomena Due to Ion Implantation Damage and Arsenic and Phosphorous Co-Diffusion", Journal of Applied Physics, Vol. 67, No. 4, Feb. 15, 1990.
It must be emphasized that even single dopant modeling, using standard approaches, presents a maze of conflicting interpretations (see, for example, Morehead et al, "Enhanced `Tail` Diffusion of Phosphorous and boron in Silicon: Self-Interstitial Phenomena", Appl. Phys. Left. 48, 151 (1986) and J. C. C. Tsai et al., "Point Defect Generation During Phosphorous Diffusion in Silicon", J. Electrochem. Soc. 134, 2348 (1987), as well as extensive sets of coupling arrangements (see, for example, B. J. Mulvaney, et al., "The Effect of Concentration-Dependent Defect Recombination Reactions on Phosphorous Diffusion and Silicon", Journal of Applied Physics, Vol 67, No 6, Mar. 15, 1990.
The difficulty resides in the fact that the explanations are made after the fact and are done as each new experiment produces unanticipated results (see, for example, Willoughby, et al., and Deaton, et al.).